Device for inserting and removing a bone nail

ABSTRACT

An instrument for inserting and removing a bone nail connected to a rod is provided. The instrument includes a head element that has a guide surface for guiding the head element along the guide rod. The head element is cylindrical or barrel-shaped, and the guide surface is formed by an axial channel in the head element, and has a lateral access which is formed in the head element. The access is used to introduce the guide rod into the axial channel, in such a way that the head element is secured to prevent it from being removed from the guide rod in the lateral direction.

BACKGROUND OF THE INVENTION

[0001] The invention relates to a device for inserting and removing abone nail, along a guide rod that is connected with the bone nail orwith an instrument that is connected with the bone nail.

[0002] The use of bone nails to aid in the healing of fractures isknown. European patent EP 0 528 128 B1 shows a locking nail to correctfemur fractures in the middle and trochanter region. In order to drivethe nail in or remove it, the locking nail is screwed into an aiming orsetting device at its end. For orientation for the operator, the aimingdevice has a guide rod that points in the longitudinal direction of thenail to be set in.

SUMMARY OF THE INVENTION

[0003] During the setting process of the locking nail, a medium pressureis exerted on the setting device, driving the nail into the bone. Smallrotational movements of the locking nail facilitate its replacement. Asa rule, driving the nail in with a hammer should be avoided, since therisk of damaging the bone to be treated is too great. Sometimes,however, it is necessary to drive the nail in with light taps. For this,it is known to use a slit or slotted hammer. The hammer, which is guidedalong the guide rod with the slit, ensures that the force applied withthe hammer taps runs in the longitudinal direction of the nail. When thelocking nail is supposed to be removed from the bone, for example, theguide rod is provided with a stop at the end pointing away from thebone. The slit hammer is arranged on the guide rod and the locking nailis removed by tapping the hammer against the end of the guide rod.

[0004] The invention is based on the task of making available a devicefor driving in and removing a bone nail along a guide rod, which devicehas a structure such that guidance of the tool is made reliablypossible, while providing ease of handling.

[0005] The device according to the invention, for driving in andremoving a bone nail of the type indicated above, is secured to preventlateral removal from the guide rod. Lateral access to an axial channelmakes it possible to set the head element against the guide rod, and tosecure it there to prevent it from accidentally slipping off, or toprevent missing the bone nail with the hammer. Such a secured guide isparticularly advantageous when removing the nail. The cylindrical orbarrel-shaped structure of the head element gives the operator a clearview of the locking nail, i.e. its aiming device, when using the deviceaccording to the invention. It is preferred that the cylindrical headelement is provided with tapping surfaces at its faces.

[0006] In the preferred embodiment of the invention, the lateral accesspossesses three segments connected with it, where a central segmentstands perpendicular to the channel and two end segments that eachfollow the central segment run in an axial direction along the channel,in each instance, where the end segments are aligned in such a way thatthe head element set onto the guide rod with the central segment is putinto a secured, locked position by means of a rotation during which theend segments take up the guide rod. Preferably, the central segment isat 90° perpendicular to the guide direction, so that a 90° rotation ofthe head element is necessary in order to achieve the locked position.The head element can be provided with a handle element that preferablypoints in the radial direction of the head element.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A preferred embodiment of the device according to the inventionis explained in greater detail on the basis of the following figures.These show:

[0008]FIG. 1 is a hammer according to the invention in a perspectiveview;

[0009]FIG. 2 is a slit hammer from the known state of the art;

[0010]FIG. 3 is a hammer according to the invention, set onto the guiderod, and

[0011]FIG. 4 is a hammer according to the invention, in its positionsecured on the guide rod.

DETAILED DESCRIPTION

[0012]FIG. 1 shows a hammer 10 according to the invention with a handleelement that is composed of a hand piece 12 and a shaft 14 that projectsfrom it. The hand piece 12 possesses a rectangular cross-section and isslightly angled at its free end. In the preferred embodiment, the shaft14 that projects from the hand piece 12 is thinner and possesses anessentially round cross-section. The shaft 14 ends at the head 16, whichhas an essentially cylindrical shape in the preferred embodiment shown.If the head element 16 is not provided with a handle element, the headelement can be held along its circumference wall.

[0013] The head 16 is provided with an access opening 18, whichpossesses end segments 20 and 24 as well as a central segment 22. In theview shown, the second end segment 24 is covered. The access 18 has awidth that is greater than the diameter of the guide rod. The centralsegment 22 of the access 18 is perpendicular to the longitudinaldirection of the head element 16, and extends from the surface to beyondthe center longitudinal axis of the cylinder. The access 18 leads to theaxial channel 19, which runs through the head element in an axialdirection.

[0014]FIG. 2 shows a slit hammer from the state of the art. The headelement 25 is shaped essentially in cube form. The slit 26 is sized tohold the guide rod 28 which extends along the longitudinal direction ofthe head.

[0015]FIGS. 3 and 4 explain how the hammer according to the invention isattached to the guide rod 28. In this connection, parts that are thesame as in FIG. 1 are indicated with the same reference symbol. Theguide rod 32 has a tapping element 30 on one side, against which thehammer is tapped to remove the bone nail. The guide rod 28 is connectedwith one end of the bone nail at its end (not shown). To drive the bonenail in, an additional tapping element (not shown) can be arrangedbetween the bone nail end and the head 16.

[0016] The central segment slot or slit 22 of access 18 intersects thecontinuous longitudinal bore for receiving rod 28 formed by oppositelyextending channel or bore portions 20, 24 which portions extend onopposite sides of the barrel or cylinder 16 from opposite ends thereofto the central segment 22. Each end portion 20, 24 is partially open inthe lateral direction to opposite sides of the head 16. Thus, rod 28 canbe placed in slot 22 across head 16 and rotated 90° (into alignment withthe longitudinal axis of rod 28) to lock the hammer 16 on the rod 28.

[0017] To drive the nail in, the hammer is set onto the guide rod 28with its central segment. By means of a rotational movement around thelongitudinal axis of the shaft 14, in a direction of the arrow A, theslits or end segments 20, 24 capture the guide rod 28. The securedposition is shown in FIG. 4. The hammer can be guided along the guiderod into the nail end with the head element 16, thereby preventing thehammer from being accidentally removed from the guide rod 28. The face32 serves as a tapping surface in this position, interacting with thetapping element 30, to remove the bone nail. Removal of the hammeraccording to the invention from the guide rod takes place by means of arotational and pulling movement.

[0018] Although the invention herein has been described with referenceto particular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A device for driving in and removing a bone nail connected to a rodthe bone nail comprising a head element that has a guide surface forguiding the head element along the guide rod, the head element isgenerally cylindrical or barrel-shaped, and the guide surface is formedby an axial channel in the head element, and a lateral access is formedin the head element via which the guide rod is introduced into the axialchannel, the lateral access is formed in such a way that the headelement is secured to prevent it from being removed from the guide rodlaterally.
 2. The device according to claim 1, wherein the access to thechannel has three segments of which a central segment forming thelateral access runs perpendicular to the axial direction, and two endsegments that follow the central segment each running in an axialdirection, where the end segments are aligned with the central segmentin such a way that the head element that is set onto the guide rod withthe central segment is put into its secured position by means of arotation (A) during which the end segments capture the guide rod.
 3. Thedevice according to claim 2, wherein the central segment essentiallyforms a right angle with the end segments.
 4. The device according toclaim 3, wherein the central segment is arranged centered on the headelement in the axial direction.
 5. The device according to claim 2,wherein the central segment is arranged centered on the head element inthe axial direction.
 6. The device according to claim 1, wherein ahandle element is provided on the head element.
 7. The device accordingto claim 6, wherein the head element is connected with the handleelement in the radial direction.
 8. The device according to claim 6,wherein the head element has tapping surfaces at the faces.
 9. Thedevice according to claim 7, wherein the head element has tappingsurfaces at the faces.
 10. An instrument for inserting and removing abone nail from a bone comprising: a guide rod having a first end forcoupling to an end of the nail; a hammer element with contact facesremovably coupled to said guide rod for sliding engagement therewith ina longitudinal direction, the hammer element having partially openchannels aligned along an axis of said hammer element extending in saidlongitudinal direction and an access channel extending in a directionlaterally of said longitudinal direction intersecting said partiallyopen channels.
 11. The instrument as set forth in claim 10 wherein anend of said rod opposite said first end includes a handle.
 12. Theinstrument as set forth in claim 10 wherein the access channel extendslaterally at 90° to said longitudinal direction.
 13. The instrument asset forth in claim 10 wherein the head element has tapping surfaces atthe faces.
 14. A method for inserting or removing a bone nail from abone comprising: coupling a rod to a first end of the bone nail;attaching a removable hammer element to said rod for sliding engagementtherewith in a longitudinal direction, said hammer element havingpartially open channels aligned along an axis of said hammer elementextending in said longitudinal direction and an access channel extendingin a direction laterally of said longitudinal direction intersectingsaid partially open channels; inserting said rod in said access channelin a direction laterally to said longitudinal direction and rotatingsaid hammer element so that said partially open channels are inalignment with said rod; sliding said hammer along said rod along saidpartially open channels; and contacting a surface connected to said nailwith said hammer element to either remove or insert the nail.